/Engine/Source/Editor/MaterialEditor/Public/MaterialEditingLibrary.h
Get the current scalar (float) parameter value from a Material Instance
static float GetMaterialInstanceScalarParameterValue ( [UMaterialInstanceConstant](API\Runtime\Engine\Materials\UMaterialInstanceConstant) * Instance, [FName](API\Runtime\Core\UObject\FName) ParameterName, EMaterialParameterAssociation Association )